This set of Extractive Metallurgy Multiple Choice Questions & Answers (MCQs) focuses on “Smelting”.
1. The process in which ore or mineral is heated using a reducing agent to extract a base metal is called ______
a) Smelting
b) Oxidation
c) Roasting
d) Calcination
View Answer
Explanation: Smelting is a process in which ore or a mineral is heated to extract a base metal. It uses a reducing agent like carbon to decompose the mineral. This process removes other elements as slag and leaves behind the base metal.
2. Which of the following we do not get as a product in a smelting process?
a) Base metal
b) Slag
c) Gangue
d) Gases
View Answer
Explanation: In all smelting process, minerals, gangue, a reducing agent and flux is used as reactants and we get a base metal, slag and gases as products.
3. Why is flux added during a smelting process?
a) To increase the gangue material
b) To decrease the formation of slag
c) Acts as a reducing agent
d) To convert the unwanted elements into slag
View Answer
Explanation: Flux is added in the smelting process to decrease gangue material and convert the unwanted elements into slag. Gangue is less fusible so flux is added to form a slag, which is easily fusible. Flux decreases the fusion temperature and also the viscosity of the slag.
4. The base metal that we receive at the end of a smelting process is in which state?
a) Solid
b) Liquid
c) Gases
d) Dust
View Answer
Explanation: The products that we obtain at the end of a smelting process is in a liquid state. We obtain some material in a solid-state as dust which is released into the air with the gases. The base metal is in a liquid state.
5. In which type of smelting process, a reducing agent is not used?
a) Reduction smelting
b) Flash smelting
c) Matte smelting
d) Oxidation smelting
View Answer
Explanation: In the matte smelting process, a reducing agent is not used. In this process, sulphide itself acts as a reducing agent. In this process, sulphide ore is fused with flux to produce molten matte. The product that we get after this process is molten matte and slag.
6. Flux is chosen for a particular smelting process after seeing which of the chemical property?
a) Chemical nature of the gangue
b) Temperature
c) External source for heat supply
d) Type of furnace
View Answer
Explanation: Flux is divided considering the criteria of chemical type. Flux is chosen keeping in mind the chemical nature of gangue and also the properties of slag like density and viscosity. For acidic gangue, a basic oxide is used as a flux and vice versa.
7. Which of the following is a reducing flux?
a) KNO3
b) NaCN
c) CaF2
d) Fe3C
View Answer
Explanation: NaCN is a reducing flux. It is a strong base. It is usually used for the metallurgy of precious elements. KNO3 is an oxidizing flux and CaF2 is a neutral flux.
8. The main function of slag is to collect the gangue materials which cannot be removed.
a) True
b) False
View Answer
Explanation: The statement is correct. Slag forms a layer of unreduced gangue materials in the extraction process. It provides a medium for the impurities to get settled between slag and the metal.
Sanfoundry Global Education & Learning Series – Extractive Metallurgy.
To practice all areas of Extractive Metallurgy, here is complete set of Multiple Choice Questions and Answers.
